> can u please give me the code written in matlab for partial least square
This is an email list about R, not about Matlab.
> will you pls provide me the code written in matlab and also the exlanatiion
> to each step
You not only want someone to do the work for you, but explain what
they did as well? :-)
My suggestion is: read a good introduction to PLSR (for instance the
one found in Martens & Næs (1989) Multivariate Calibration, Wiley).
If you are not able to implement the algorithm from the description
there, you are probably better off using an existing implementation,
for instance Barry Wise's chemometric toolbox.